There is this guy in Grade 12 and I'm in grade 10. we've started talking a lot lately and i really like him. what could i say to him to make him like me more than he does now?

You can't make him like you, but you can make your friendship better. You could try finding things you have in common with him, and talk about that. Be truthful, and don't go out of your way to seem nicer to him. If he asks you something, if it seems unusual it might be because he wants you to ask him the same thing.
If you find something strongly in common, like music or sport or art, concentrate on that. Swap things, like bluetoothing over phones. Nothing big like roses on Valentine's Day.

Remember to smile.